Liz is saved by those chasing her and brought to where Reegan is keeping the aliens where she's forced to help Lennox. Doctor Taltalian returns to the space centre revealing he was acting under General Carrington's orders. The Doctor, working to decode the alien transmissions, receives a phone call threatening Liz's life. Liz, with help from Lennox, escapes from where the aliens are being kept but is immediately recaptured by Doctor Taltalian who has come too see Reegan. Taltalian gives Reegan a device to allow him to communicate with the aliens, and in return is given a time bomb to kill the Doctor. When he returns to the space centre, the bomb goes off when set, killing Taltalian. The Doctor determines this wasn't a fault and finds the device for deciphering the alien communication. One of the aliens is brought to the Space Centre where it kills Sir James Quinlan. Finding the body the Doctor does not see the alien, which was hiding in the room, now leaning over him.

Not bad this episode, though Taltalian's loss of accent in his one location scene is obvious: at the time it was filmed they hadn't decided to give Taltalian an accent. When you see this episode there's enough information there for you to join the dots and work out who's behind the alien's second kidnapping... if you hadn't guessed already! The why is perhaps a little less obvious. Liz escaping and being recaptured filled five minutes giving us some shots of her running across a field but it's an obvious time waster especially when she's recaptured so quickly. There's no colour at all in this episode but we'll make up for that over the next two.

Making his credited Doctor Who debut here is Max Faulkner as a UNIT Soldier. He'll be back in The Monster of Peladon (as a miner), Planet of the Spiders (as a Guard Captain), Genesis of the Daleks (as a Thal Guard), The Android Invasion (as Corporal Adams) & The Invasion of Time (as Nesbin) plus served as Fight Arranger on The Hand of Fear. John Lord, Masters, was previously a Yeti in The Web of Fear while Tony Harwood, Flynn, had a long history of being a monster in Doctor Who starting with a Cyberman in The Tomb of the Cybermen, a Yeti in The Abominable Snowmen, Rintan, an Ice Warrior in The Ice Warriors and another Ice Warrior in The Seeds of Death.